Spirit-level



(No Model.)

L. L. DAVIS.

SPIRIT LEVEL.

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UNITED STATES PATENT OEFICE.

LEONARD L. DAVIS, OF SPRINGFIELD, MASSACHUSETTS.

SPIRIT-LEVEL.

`SiIEEtJIlICATION forming part of Letters Patent No. 268,634, datedDecember 5, 1882, i

Application nien May 12,1881. (No model.)

To all whom it may concern: l

Be it known that I, LEONARD L. DAVIS, a citizen of the United` States,residing at Springfield, Hampden county, State of Massachusetts, haveinvented a new and useful Improvement in Spirit-Levels, of which thefollowing is a speciticati'on.

In the drawings, Figure I is a side elevation of that portion of aspirit-level to which my invention is applied, with part of thegraduated ring broken away to show the details of the adjustingarrangement, and in partial section.` Fig. 1I is a plan view ot' sameportion ot' said spiritlevel, and Fig. Ill is an enlarged detail view ofone of the adjustingscrews.

This invention relates to improvements upon the invention for whichpatent was gratited me March 17, 1868, No. 75,533, in which a revolvingbubble-case is embedded in the frame ot' a level .to have thebubble-glass adjustable'with reference to the outer frame or base ot'the level by means of screws provided with conical points `and arrangedto project inward and move against studs upon the bubble-case, havingcorresponding beveled ends, and their longer axes coincident to thatmofthe screws to, by the movement of said screws, adjust the bubble-glassinreciprocating it; and this invention consists more particularly in animproved construction and arrangement of the` adjusting mechanism t0 thebubbieglass. l Y

ln the drawings, a represents the socket or receptacle into which isinserted and in which revolves or oscillates the ring D, having thereinthe bubble ease C. The ring a. is perforated on each side, saidperforations having screw-threads cut therein, and extending to and fromone ot' the longer bearing-surfaces o f the level at a right anglethereto, and so as to consequently cut the inner surface of the ring ata tangent, and the screws d d are turned into ,the said threadedperforations, their ends e e protruding beyond the inner surface ot thering a and into the space between it and the ring D, exactly oppositeeach other. Into the ring D are placed the studs it', which may besecured in place by'any convenient and proper method, and so placed thatwhen the ring D is in place in' its socket a the studs t' fishall be inthe same vertical plane with the screws d d'. The stud t' is set intothe ring D at a distance from the stud t equal to one-fourth of thewhole circumference ot' the ringD, and they are sol arranged that whenthe bubble-case C or ring D be turned one-quarter ot a revolution thestud t' impinges against the end of screw d, as shown in dotted lilies.

I prefer to have the ends of screws dd cut square off, and the studs't't against which they come in contact of cylindrical form, though adeparture from this configuration in either would he immaterial.

The operation of my invention lis as follows: It' it is found upon trialthat the bubble-glass is not in perfect adjustment with the base ot' theframe B', and it should be necessary to depress the side E otl thebubblecase C, the screw d is turned in', and its end e', in its contactwith the stud t', forces it downward, which action elevates the otherside, F, ofthe bubble-case C, and the screw may be correspondinglyturned out, if desirable.

It will be seen that by this construction and arrangement of the partsot' the adjusting mechanism a greater latitude ot' adjustment ispossible, and that the wear Ot' the impacting-surfaces ot' studs andscrew ends can to any extent be taken up by the movement of the screw,whereas in the patented device before cited the extent of oscillationgiven to the bubble-case was limited to the distance the screws' couldmove before having their ends bring up against the ring D, and any wearof the bearing surface of the` studs served to shorten that distance.The position of the heads ot the adjustin, g,-scre\\ 's in this devicepossesses also great advantage over that occupied by the correspondingparts as formerly arranged, inasmuch as nowthe screw-driver for movingthem can be heldin a position to avoid injuring the screws, and so thattheir movement by hand can be more accurately regulated.

What I claim is- In combination'with the studs it" upon the i rotaryreciprocating ring D, the adjustingscrews d d', arranged in the frametangentially to the bubble-case, to operate substantially as shown anddescribed.

L. .L. DAVIS.

Witnesses:

H. F. HYDE, T. M. BROWN.

